This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A173923 #7 Aug 07 2021 12:00:49
%S A173923 0,1,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,1,0,0,1,1,0,0,0,0,1,1,1,1,0,0,
%T A173923 0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1,
%U A173923 1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0
%N A173923 In the sequence of nonnegative integers substitute all n by 2^floor(n/8) occurrences of (n mod 2).
%C A173923 a(n) = A173920(n+8,8).
%C A173923 a(n) = A000035(A132292(A030101(n+8)+1)).
%t A173923 Table[PadRight[{},2^Floor[n/8],Mod[n,2]],{n,0,30}]//Flatten (* _Harvey P. Dale_, Aug 07 2021 *)
%Y A173923 Cf. A001477, A079944, A173922.
%K A173923 nonn
%O A173923 0,1
%A A173923 _Reinhard Zumkeller_, Mar 04 2010
%E A173923 Sequence definition changed for clarity (see A173922).